JPS62279412A - Failure diagnosing device for actuator - Google Patents

Abstract

PURPOSE:To diagnose a failure of an actuator by simple circuit constitution by detecting abnormality of the actuator by the same means irrespective of the state of failure such as short circuit, disconnection etc., of the actuator. CONSTITUTION:When a transistor Tr T2 is OFF, electric charge is charged in a capacitor C through a resistor R3. Time constant of the charge is made sufficiently large compared with the period of pulse which is an output signal of a pulse generating means. Accordingly, when an actuator 34 is working normally, the potential at a point (e) of the output signal of an edge detecting circuit 35 remains at nearly GND level. When a point (d) of the output of the actuator 34 is short-circuited to a power source VAA, short-circuited to GND or disconnected, no rising-up edge is inputted to the edge detecting circuit 35 and the Tr T2 is not made ON. Accordingly, electric charge is charged continuously to the capacitor C, and the output of the invertor of a failure judging means 36 changes from H level to L level, and the failure is diagnosed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an actuator failure diagnosis device, and particularly to an actuator failure diagnosis device in an actuator control system using an electronic control unit.

[Prior art J] A conventional actuator failure diagnosis device performs a logical operation to determine whether current is flowing through the actuator or not, and a logical operation to determine whether the voltage at a measurement point is above or below a reference voltage. Failure diagnosis was performed using For example, in FIG. 2, the actuator 21, the battery 22 that is its driving force source, and the actuator 21
When combined with the transistor 23 that performs F, the measurement point a
The voltage state of the transistor 23 is ON, OF
F status and actuator 21 are normal, turn on battery 2
Short circuit to 10B of 2, short circuit to GND of battery 22,
There are eight states as shown in Table 1 based on the four states of disconnection of the dot. Since VCE(Sat) is the collector saturation voltage of the transistor, VCE(Sat)
It is D.

Therefore, as can be seen from Table 1, a short circuit of the dot to 10B can only be detected when the transistor 23 is ONt, and a short circuit of the dot to GND or disconnection of the dot is detected by the transistor 23. It can only be detected when it is in effect.

Table 1 [Problems to be solved by the invention] However, in many cases, the actuator failure diagnosis device does not need to know what kind of failure is occurring in the actuator, but rather whether the actuator is normal or abnormal. It would be good if it could be determined.

In other words, as you can see in the example in Figure 2 above, the point is 10B.
If there is a short circuit or disconnection to F1, the actuator 21 will switch to F1.
If the light is shorted to GND, the actuator 21 is ONL.
/, It is impossible to control the actuator 21 from the transistor 23, and even if you know the failure state, you cannot deal with it, so if you have a function that can determine whether the actuator's operation is normal or abnormal. It is enough.

Therefore, in order to know the failure state of the actuator, it is necessary for the device to have a means for detecting a short circuit of the dot to +B, a means for detecting a short circuit of the dot to GND, and a means for detecting a disconnection of the dot. This makes the process complicated and leads to an increase in costs.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and to provide an actuator failure diagnosis device that detects an abnormality in an actuator by the same means, regardless of the actuator failure condition g (short circuit or disconnection).

[Means for Solving the Problems] The present invention includes at least a manipulated variable output means that generates a signal according to a predetermined manipulated variable, a pulse generator that generates a pulse based on a predetermined same value, and at least final operation amount output means that performs calculations based on the operation amount of the operation amount output means and the operation amount of the pulse generation means and outputs the operation amount; and a drive signal output that outputs a drive signal for the actuator based on this output signal. an actuator that is driven by the drive signal to generate power; and an operation command signal for the actuator (a signal that turns the actuator ON-OFF or OFF-ON within a certain period of time based on the output signal of the drive signal output means). ) is present, and a failure determining means performs calculations based on the signal to determine a failure.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the basic configuration of the present invention includes a manipulated variable output means 11 that generates a signal according to a predetermined manipulated variable, and a pulse generator 17 that generates pulses based on a predetermined cycle. and at least the manipulated variable output means 11
a final manipulated variable output means 12 that performs calculations based on the manipulated variable of the pulse generating means 17 and the manipulated variable of the pulse generating means 17, and outputs the manipulated variable;
A drive signal output means 13 that outputs a drive signal for the actuator based on this output signal, an actuator 14 that is driven by this drive signal and generates power, and a An edge detection means 15 that outputs a signal indicating whether a signal (operation command signal) for turning the actuator 14 ON-OFF or 0FF-ON exists, and a failure determination unit that performs calculations based on this signal to determine a failure. It is equipped with means 16.

A specific example is shown in FIG. In FIG. 3, reference numeral 31 is a control unit that functions as the manipulated variable output means 11, pulse generation means 17, and final manipulated variable output means 12, and 33 is a drive signal output means (13 in FIG. 34 is an actuator (corresponds to 14 in Fig. 1), 35 is an edge detection circuit (corresponding to 14 in Fig. 1) that uses a capacitor C, a resistor R3, and a transistor T2 to output a CC if there is no rising edge of the input signal for a certain period of time. (corresponding to 15 in FIG. 1), 36 is a failure determination circuit using an inverter (corresponding to 16 in FIG. 1).

Calculations are performed from the output signal of the manipulated variable output means and the output signal of the pulse generator, and a final operation signal including pulses for fault diagnosis is obtained at regular intervals. In this embodiment, these means include a CPU 31a, a memory 31b,
Control unit 3 consisting of interface 31c
It is realized with 1 software. The output signal from the control unit 31 drives the transistor T1, which is the drive signal output means 33, and the actuator 34 operates. Here, normally, the manipulated variable of the manipulated variable output means is reflected and the transistor T1, which is the drive signal output means 33, is driven, but a short pulse generated by the output signal of the pulse generating means is inputted as the manipulated variable at regular intervals. Therefore, the transistor T1 is turned off at regular intervals.

This ON-OFF signal causes the transistor T2 of the edge detection means 35 to turn on at the rising edge, and when the transistor T2 turns on, the charge stored in the capacitor C is discharged.

On the other hand, when this transistor T2 is OFF, the resistor R
An electric charge is charged to the capacitor C through 3, but since the time constant of this charge is sufficiently large compared to the period of the pulse generated by the output signal of the pulse generation means, if the actuator is operating normally, the edge detection circuit 35
The potential of the output signal @ (point e) remains almost at the GND level. However, if the point d is short-circuited to VAA, short-circuited to GND, or disconnected, a rising edge is no longer input to the edge detection circuit 35, and the transistor T2 is no longer ONL.

Therefore, the capacitor C continues to be charged, and finally exceeds the threshold voltage of the inverter of the failure determination circuit 36, and the output of the inverter goes from the "H" level to "L I+".
The level changes and the failure is diagnosed.

[Effects of the Invention] As described above, the present invention enables failure diagnosis of an actuator with a simple circuit configuration, and also brings about effects such as device simplification and cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing a conventional example, and FIG. 3 is a circuit diagram showing a specific example of one embodiment of the present invention. 11... Manipulated amount output means 12... Final manipulated amount output means 13... Drive signal output means

Claims (1)

[Claims] (1) A manipulated variable output means that generates a signal in accordance with a predetermined manipulated variable, a pulse generator that outputs a pulse-like manipulated variable based on a predetermined period, and at least the manipulated variable output means. final manipulated variable output means that performs calculations based on the output signal and the output signal of the pulse generating means and outputs a manipulated variable; and a drive signal that outputs a drive signal for the actuator based on the output signal of the final manipulated variable output means. an output means, an actuator that generates power in response to an output signal of the drive signal output means, and an actuator that determines whether or not an operation command signal for the actuator is present within a certain period of time based on the output signal of the drive signal output means. An actuator failure diagnosis comprising: an edge detection means for outputting a signal indicating a failure of the actuator; and a failure determination means for performing calculation based on the output signal of the edge detection means and outputting a signal corresponding to a failure determination of the actuator. Device.